1. Field of the Invention
The present invention relates to a gaming machine such as a slot machine, and a method of detecting fraud in the same. More particularly, the present invention relates to a gaming machine constructed with a view toward preventing the fraud of a player being able to play a game without inserting a coin, and a method of detecting such fraud.
2. Description of the Related Art
A gaming machine such as a slot machine is operated in response to insertion of coins, medals, tokens or other disks (herein referred to as coins) into a coin slot. The gaming machine incorporates a CPU, which effects control according to a stored program. The CPU receives signals generated by signal generators, including switches and sensors, so as to execute a control sequence: when a coin is inserted, a coin sensor sends a coin-detect signal at a High level to the CPU, which in response to the coin-detect signal brings a starter lever to a standby condition for actuation. Then the starter lever is operated, to cause a starter switch to generate a start signal at a High level. The CPU in response to the start signal starts rotating the three reels simultaneously. Stop buttons are next depressed, to generate a reel-stop signal at a High level. The CPU controls a reel control circuit to stop the reels. If symbols are stopped along a winning line, namely a line defined horizontally or diagonally across the reels, in a combination predetermined as winning, then the CPU causes a coin dispenser to pay out coins of a number associated with the winning grade of the symbol combination, to end one game. If symbols are stopped not in a wining combination, the game ends in a loss.
Conventional slot machines, however, suffer from the disadvantage of being vulnerable to fraud, by use of an additional false connection FC between signal lines of the coin sensor and of one of the stop buttons (FIG. 2). A dishonest player depresses the stop button associated with the additional connection FC, causes the additional connection FC to transmit a reel-stop signal through a signal line of the coin sensor, and this sends the High-level signal to the CPU, which would recognize the reel-stop signal as a coin-detection signal. The CPU would bring the starter lever to standby for actuation, despite the fact that there has been no insertion of a coin. This would require that the player have the cooperation of an employee in possession of keys to the amusement facilities. A front panel of the slot machine would be unlocked and opened by use of a key. It is thereafter easy to attach a piece of wire to interconnect the two signal lines.